How to perform comparison on histograms with different number of bins?

Hi all,

I was hoping to get some help from the people of this excellent forum.

My problem has to do with comparing two histograms which carry 1D data but with different number of bins. e.g a histogram with 10 1D values and a histogram with 20 1D values. The first value of the first histogram always matches the first value of the second and this is also true for the end values.

My question is how can I perform for example L1 distance between the two histograms which have different total number of values?

I hope I have set the question right as English in not my mother language.